摘要
吐哈盆地K22气井储层埋藏深度3 720 m,地层温度110℃,压力系数1.01,具有低孔隙度、低渗透率特性。邻井岩心流动实验为强水敏、强—极强水锁;所在区域平均应力梯度为0.025 7 MPa/m。因此,基于新型表面活性剂研究了一种新型清洁压裂液,并做了有关的测试分析。RS600流变仪评价测试结果表明,该压裂液黏温性能稳定、黏度可达60 mPa.s;采用控制应力流变仪测试的该压裂液弹性模量远大于黏性模量,因而具有优良的黏弹性、流变性和携砂性能;Fann35黏度计测试结果表明,在辅剂作用下易于破胶,对储层伤害小;环路实验装置测试结果表明,该压裂液流动摩阻低。现场应用表明:摩阻仅为清水摩阻的1/3,成功加砂44.1 m3,平均砂比20.6%;施工过程液体性能稳定,压后破胶彻底、返排率达到79.26%;能够满足中等加砂规模的要求。该清洁压裂液成本相对较低且配制简单,有效地解决了在高温气井难以破胶的问题,对低渗透高温气藏压裂改造提供了技术支持。
The pay zone in the K22 gas well,Turpan-Hami Basin,is 3720 m deep with the temperature of 110℃ and the pressure coefficient of 1.01,and is of low porosity and low permeability.From the core experimental analysis,the pay zone is found to be strong water sensitive,strong to extremely strong water-blocking,and the average pressure gradient there is about 0.0257 MPa/m.Therefore,based on a novel surfactant,a new clean-fracturing fluid was developed and relevant tests were carried out.Specifically,its viscosity vs.temperature is stable according to the evaluation of the RS600 rheometer,and the viscosity is up to be 60 mPa·s;its elastic moduli is much larger than loss moduli according to the tests by the stress-controlling rheometer,which means excellent visco-elastic property,rheological property and proppant carrying capacity;it tends to gel breaking when processed by supplementary additives and does little harm to the formation according to the tests by the Fann35 viscometer;it also shows low flow resistance through tests of the loop equipment.A field application shows that its resistance is only one-third of that of water friction and 44.1 m3 proppant has been injected into the formation with an average sand ratio of 20.6%.During fracturing treatment,the liquid shows stable performance and completely broken gel with a flow-back rate as high as 79.26%.This satisfies the requirements of the moderate-rate sand adding.This low-cost,easily prepared clean fracturing fluid effectively solves the problem of difficult gelout in a high-temperature gas well effectively.Moreover,it provides technical support for the fracturing in low-permeability and high-temperature gas reservoirs.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2011年第7期43-46,106-107,共4页
Natural Gas Industry
关键词
低渗透率
高温气藏
气井
水力压裂
清洁压裂液
敏感性
黏弹性
成本
吐哈盆地
Turpan-Hami Basin,low permeability,high temperature gas reservoir,gas well,hydraulic fracturing,clean fracturing fluid,formation sensitivity,visco-elastic property
